This is an extended conference proceedings report [Long Paper] based on a shorter contributed report at the same conference. A variety of computerized learning platforms exist. In mathematics, most include sets of problems to complete. Feedback to users ranges from a single word like "Correct!" to offers of hints and partially- to fully-worked examples. Behind-the-scenes design of such systems also varies--from static dictionaries of problems to responsive programming that adapts assignments to users' demonstrated skills within the computerized environment. This report presents background on digital learning contexts and early results of a mixed-methods study that included a cluster randomized controlled trial design. The study was in community college algebra classes where the intervention was a particular type of web-based activity and testing system. [This paper was published in: Weinberg, A., Rasmussen, C., Rabin, J., Wawro, M., and Brown, S. (Eds.), "Proceedings of the 20th Annual Conference on Research in Undergraduate Mathematics Education," p638-645. San Diego, CA (2017).]